Processing of allochthonous macrophyte subsidies by sandy beach consumers: estimates of feeding rates and impacts on food resources

Allochthonous subsidies of organic material can profoundly influence population and community structure; however, the role of consumers in the processing of these inputs is less understood but may be closely linked to community and ecosystem function. Inputs of drift macrophytes subsidize sandy beach communities and food webs in many regions. We estimated feeding rates of dominant sandy beach consumers, the talitrid amphipods (Megalorchestia corniculata, in southern California, USA, and Talitrus saltator, in southern Galicia, Spain), and their impacts on drift macrophyte subsidies in field and laboratory experiments. Feeding rate varied with macrophyte type and, for T. saltator, air temperature. Size-specific feeding rates of talitrid amphipods were greatest on brown macroalgae (Macrocystis, Egregia, Saccorhiza and Fucus). Rates for large individuals of both species ranged from ∼40 mg wet wt individual⁻¹12 h⁻¹ on brown macroalgae to negligible feeding by M. corniculata on a vascular plant (surfgrass). Amphipod growth rates were also greatest on Macrocystis and lowest on surfgrass, Phyllospadix. For a Californian beach with substantial inputs of macrophyte wrack (>70 kg wet wt m⁻¹ month⁻¹ in summer), we estimated that the population of talitrid amphipods could process an average of 55% of the palatable Macrocystis input. Our results indicate that talitrid amphipod populations can have a significant impact on drift macrophyte processing and fate and that the quantity and composition of drift macrophytes could, in turn, limit populations of beach consumers.     

A general approach to transform a lake model for one radionuclide (radiocesium) to another (radiostrontium) and critical model tests using data for four Ural lakes contaminated by the fallout from the Kyshtym accident in 1957

This paper presents results of a model test carried out within the framework of the COMETES project (EU). The aim of the work was to change the structure of the MOIRA lake model for radiocesium so that it can be applied more generally for, in principle, all types of radionuclides and heavy metals. This general lake model is used within the MOIRA decision support system (DSS; MOIRA and COMETES are acronyms for EU-projects). The model is based on a set of differential equations and a specific modelling structure. It incorporates all important fluxes to, from and within lakes in a general manner. Yet the model is driven by a minimum of variables accessible from standard maps and monitoring programs. The model can be separated into two parts, a general part with equations applicable for all types of water pollutants and a substance-specific part. This model has previously been validated for 137Cs from many lakes covering a wide domain and yielded excellent predictive power. The alterations discussed in this work are meant to be general and radiostrontium is used as a typical element. Radiostrontium is known to be more mobile than radiocesium and all abiotic parts of the model handling fixation and mobility have been altered. The new model for 90Sr has been critically tested using data from four lakes heavily contaminated with 90Sr from the Kyshtym accident in the Southern Urals, Russia, using empirical data from a period from 1958 to 1995 for 90Sr in fish (here goldfish), water and sediments.     

Biogeochemical distinction of methane releases from two Amazon hydroreservoirs

Biogeochemical distinction of methane emissions to the atmosphere may essentially rely on the surface area and morphometry of Amazon hydroreservoirs. Tucuruí (deep) and Samuel (shallow) reservoirs released in average 13.82 ± 22.94 and 71.19 ± 107.4 mg CH₄ m⁻² d⁻¹, respectively. δ¹³C–CH₄ values from the sediments to the atmosphere indicate that the deep reservoir has extended methanotrophic layer, oxidizing large quantities of light isotope methane coming from the sediments, while sediment-generated methane can easily evade the shallow reservoir.     

Monitoring microbial biomass and respiration in different soils from the Czech Republic--a summary of results

The microbial biomass (Cbio), respiration (basal respiration (BR) and potential respiration (PR)), and derived indices for 520 independent soil samples of 117 different soils from the Czech Republic were statistically analysed. The broad range of soil samples allowed the stepwise breakdown of the database into six reasonable categories of soil: arable soils, loamy grassland soils, sandy grassland soils with weak organic matter content, sandy grassland soils with moderate organic matter content, forest soils with moderate organic matter content, and forest organic soils with rich organic matter content. Because soil microbiology lacks benchmarking values, the ranges of the microbial characteristics for these categories were stated and are presented here. The separation into soil groups narrowed the ranges enough to be useful for comparative purposes. The groups displayed significant differences in basal microbial parameters. The lowest microbial biomass was found in arable soils and grassland sandy soils with weak organic matter content. The highest microbial biomass was shown by loamy grassland soils and organic forest soils. Respiration displayed similar results to the microbial biomass. The derived indices revealed less significant differences confirming their inner-standard nature. The relationships between the soil contamination and microbial parameters were not explored because of the confounding effect of soil organic matter. However, it was not shown by the category of grassland sandy soils with weak organic matter content suggesting they could be especially suitable for the biomonitoring of harmful effects of chemicals on soil microorganisms.     

Safe alternative cancer therapy using electromagnetic fields

This article highlights recent research on the beneficial use of selected low frequency electromagnetic fields (EMF) as a safe alternative therapy for treatment of cancer and other health problems. It is shown that EMF therapy provides a safe alternative and adjunct modality for the treatment of cancer and other health problems, and therefore, research in this field deserves more support. The paper also discusses some reports and hypothesis of potential risk of human exposure to low frequency EMF, mainly to the power line frequency of 60 Hz.     

17th ICCE Satellite Event University Education in Environmental Sciences

Environmental Science and Pollution Research - Recently, nearly 500 study programmes related to environmental disciplines were detected in Europe (Lammel et al, Environ Sci Pollut Res 21:7211-7218...     

The use of some plant-derived products as effective alternatives to antibiotic growth promoters in organic poultry production: a review

Environmental Science and Pollution Research - Improving poultry production, increasing poultry immunity, and reducing the disease spreading can be achieved by adding various potentially valuable...     

How could sympatric megaherbivores coexist? Example of niche partitioning within a proboscidean community from the Miocene of Europe

Although low in diversity, megaherbivores (mammals weighting over 10(3) kg) and especially proboscideans have a powerful impact on the structure and dynamics of present-day ecosystems. During the Neogene (23 to 2.6 Ma) of Europe, the diversity and geographic distribution of these megaherbivores was much greater. Nonetheless, their role in past ecosystems is unclear. Nutrition is one of the main bonds between organisms and their environment. Therefore, the ecology of organisms can be inferred from their dietary habits. The present study is aimed at characterizing the feeding habits of diverse megaherbivores through dental microwear analyses. This method was applied on cheek teeth of three sympatric species of proboscideans from the middle/late Miocene of the Molasse Basin in Southern Germany: Gomphotherium subtapiroideum, Gomphotherium steinheimense, and Deinotherium giganteum. The microwear signatures are significantly different between these taxa, suggesting differences in feeding habits and ecological niches within a woodland environment. D. giganteum probably browsed on dicotyledonous foliages whereas the two species of gomphotheres were neither strict grazers nor strict browsers and instead probably fed on a large spectrum of vegetal resources. The differences of occlusal molar morphology between the two gomphotheres are supported by the dental microwear pattern. Indeed, G. subtapiroideum probably ingested more abrasive material than G. steinheimense. Thus, our results suggest that these proboscideans did not compete for food resources.     

Particle formation due to brake wear,influence on the people health and measures for their reduction: a review

Environmental Science and Pollution Research - For achieving the desired vehicle speed, the IC engine is very important, while for further vehicle speed maintaining and adaptation to road...